Generally, stop cocks which are used on railroad cars are classified as E4103, E4104, and E4105 by the Japanese Industrial Standard (JIS). These standard cocks are normally the ones employed in conjunction with pipe mounts or mounting brackets. A simple form of stop cock includes a hollow body having a tapered plug which has an opening through it. When the plug is turned so that the holes in it correspond to the ports in the body, the liquid flowing in the pipe can pass through the cock. When the plug is turned so that the openings do not correspond, the flow is stopped.
An example of a prior art plug cock for pipe seat brackets for usage on railroad cars is shown and disclosed in Japanese official report invention or utility model registration application No. 59-152272. A specific embodiment based on this will be explained in detail below in relation to FIGS. 6 and 7. It will be seen that FIG. 6 is a partial sectional front view of a conventional plug-type stop cock while FIG. 7 is a plan view of the cock of FIG. 6.
As shown in both FIGS. 6 and 7, the stop cock includes a valve body having a pair of apertured mounting flange portions 10. This is, the two flanges 10 are located or formed on opposite sides of the valve body 1. The flanges 10 are adapted to be mounted to a pipe seat bracket surface 7 which is shown by phantom lines 7. A pair of bolt holes 10a and 10b are drilled at the end lobe portions of the flanges 10. The bolt holes 10a and 10b are in horizontal alignment along the longer side of the valve body 1. First and second passages 11 and 12 are drilled in the middle portion of the valve body 1. The open ends of the passages 11 and 12 face the open end plane 10c of the flange 10. The end plane 10c faces the planar surface of the pipe seat bracket 7. As shown in FIG. 7, the valve body 1 includes a first hole 13 which is formed on its outward end. The first hole 13 is connected to the first passage 11. The valve body 1 also includes a second hole 14 which is formed towards its outer extreme. The second hole 14 is connected to the second passage 12. As noted above, the open ends of the passagese 11 and 12 are formed parallel to the end planar surface 10c. A conical-shaped cock plug or frustrum of cone valve 8 is vertically-inserted between the first hole 13 and the second hole 14. It will be appreciated that the valve plug 8 is rotatable about its longitudinal axis. The valve plug 8 has a through opening 80 formed in the center thereof.
As shown, a movable handle 6 is fixed at the top end of the extension of the valve plug 8 outside the valve body 1 to open and close the valve plug 8 when it is rotated.
In viewing FIG. 6, it will be seen that a bottom cap member 9 is located on the end opposite the handle 6. That is, a threaded cap member 9 is screwed into the bottom end of the valve body 1. An internal pressure chamber 91 is formed between the bottom end of plug 8 and the upper, inner surface of cap 9. The chamber 91 is connected to the opening 80 via a passageway (not characterized). A spring member 92 is located in the pressure room 91 to force the valve plug 8 towards the handle side. That is, the compression spring 92 urges the conical plug 8 upwardly, as viewed in FIG. 6. In viewing FIG. 7, it will be seen that a pair of mounting holes 7a and 7b are formed in the seat 7, which are in alignment with bolt holes 10a and 10b. A pair of fluid passages 7c and 7d are formed in the seat 7, which are in alignment with the passages 11 and 12, respectively. The distance between the centers of the first hole 13 and the second hole 14 is represented by the means length L1, while the distance between the centers of the two bolt holes 10a and 10b is represented by the mean length
In viewing FIGS. 6 and 7, it will be appreciated that the valve plug 8 is shown in its closed position in which there is no communication between the first hole 13 and the second hole 14 of the stop cock 1. Now, if the handle 6 is rotated by 90.degree. to the right, the holes 13 and 14 will be fluidly interconnected via the passageway 80.
As described above, it was common practice to employ an apertured conical-shaped cock plug to close or to open the passages of a stop valve. However, such previous types of cocks have several disadvantages, such as, poor sealing and the need of great force to operate the handle 6. For these and other reasons, there has been a trend in recent years to replace the frustro-conical plug valves used in railroad cars with ball-shaped plug valves. An example of a cock valve with a ball-shaped valve plug is shown and described in Japanese official report invention or utility model registration application No. 60-113381. An altered cock for use with pipe seats from a pipe-mounted cock is illustrated in FIGS. 8 and 9 of the drawings. It will be seen that FIG. 8 is a sectional view taken along section line D--D of FIG. 8. It will be noted that the same numbers are given to the equivalent or same parts as those shown in FIGS. 6 and 7. For convenience purposes, a detailed description of all of the parts will not be repeated.
In this second conventional embodiment, an inner hole 15 is formed between the first hole 13 and the second hole 14 in valve body 1. The open ends of holes 13 and 14 are aligned flush with the end plane 10c of the flanges 10. A ball-shaped valve plug 2 is housed and mounted for rotation in the inner hole 15 of the valve body 1. The valve plug 2 has a central opening or bore 20 which is adapted to open a fluid passage between the holes 13 and 14 when in its open position, and to close communication between the holes 13 and 14 when in its closed position. The valve plug 2 is supported at its two sides by two hollow seal seats 3. A hollow flat spring or belleville washer 4 is disposed between one of the seats 3 and the valve body 1. A hollow spacer 30 is located between the spring washer and one of the seats 3, against the valve plug 2 to sealingly rest against the two seats 3. A valve plug operating stem 5 is vertically-inserted into the valve body 1 which is located in the inner hole 15, as shown in FIG. 8. That is, the lower end of the inserted stem 5 includes a reduced portion which extends into and is locked in the slot or groove 21 provided therefor in the valve plug 2. A movable or rotatable handle 6 is fixed at the upper end of the valve stem 5, as shown in FIG. 8. Thus, the handle 6 is located on the upper outside portion of the valve body 1 and is adapted to be turned manually to thus rotate the stem 5, the reduced portion, and the ball 2.
In viewing FIGS. 8 and 9, it will be noted that the valve plug 2 is shown in its open position for connecting the two holes 13 and 14. Now, when the handle 6 is rotated by 90.degree., the valve plug 2 will close the passage between the holes 13 and 14.
It will be seen that in a stop cock for pipe seats having a ball-shaped valve plug in the conventional design illustrated in FIGS. 8 and 9, the center-to-center dimension L1' between the first hole 13 and the second hole 14 is larger than the center-to-center dimension L1 of a conventional stop cock for pipe seats having a frusto-conical valve plug, as shown in FIGS. 6 and 7. Because of its ball-shape, the diameter of the valve plug 2 is comparatively larger and having an opening size equivalent to the opening 80 of the cone-shaped valve plug 8. In addition, the seats 3, which seal, bed, and support the ball valve plug 2, and the spring 4 which provides uniform sealing, are located along the side of valve plug 2 between the first and the second holes 13 and 14. This also results in a problem because the center-to-center dimension L2' between the bolt holes 10a and 10b is larger than the center-to-center dimension L2 between bolt holes 13 and 14 of the frustro-conical stop cock. Thus, it is impossible to directly attach the ball-shaped stop cock of FIGS. 8 and 9 to a central piping seat bracket 7, as shown in FIGS. 6 and 7. Accordingly, the two stop cocks are not compatible devices and cannot be used as direct replacements for each other.
This problem is due to the design which requires the first hole 13 and the second hole 14 to be in straight alignment, and the pipe seat 7 to be parallel with the planar surface 10c of the flange 10. The first hole 13, the spring 4, the seats 3, the ball-shaped valve plug 2, as well as the second hole 14, of FIGS. 8 and 9 are incompatible with the fluid passage holes and bolt holes of FIGS. 6 and 7.